Wednesday, March 22, 2006

March 22 notes: eggs over easy ...

You may have noticed that the eagles occasionally take a brief respite from incubation and seem to be arrange items in the middle of the nest. Eagles, like all birds, need to turn their eggs frequently during incubation. An air cell forms in the egg shortly after the egg is layed and grows larger during incubation. The parents need to turn the egg to prevent the developing embryo from adhering to the eggs shell, which stops development. As far as we know, biologists have not documented how often eagles turn their eggs. Perhaps you can gather some information on this behavior by watching the web camera.

Bald eagles typically lay only one clutch per year. Eagles on the coast of Maine may lay a clutch as early as mid-February, although early March is more typical. In northern Maine, where the lakes are still frozen over and the snow pack still has weeks before it melts, egg-laying may be delayed into early to mid-April. We have seen eagles many times blanketed in an early spring snow, but remaining faithful to their incubation duties.

Bald eagles lay one to three eggs, but two is most common. They are dull white in color and about the size of a goose egg. The eggs are layed about 3 or 4 days apart. Incubation begin when the first egg is layed, which means that eggs in a clutch will hatch several days apart. "Asynchronous hatching" is a common in strategy in birds of prey. One chick will always be the oldest and largest and dominant over its siblings. In poor food years, only the oldest chick may survive, but in good years all chicks in a brood survive.

Both the male and female eagle develop a brood patch - a bare area of skin in the center of the chest to keep the eggs warm. the female eagle does most of the incubating, but the male also returns to the nest to help. If you're lucky, you may see a nest exchange occur on the web camera. The male will often bring food to the nest for the female while she is incubating.

Adults show great concern for their fragile eggs and walk very carefully around the nest with clenched feet to avoid breaking the eggs. We would be interested in hearing from you if you observe no eagles on the nest during the incubation period. Adults will occasionally leave the eggs for a brief time (perhaps on warmer days in late incubation). If they do, they sometimes cover the eggs with grass and pine needles from the nest bowl to avoid predation by crows. -- Mark McCollough, U. S. Fish and Wildlife Service

11 Comments:

Anonymous Jane Edwards said...

Thanks for writing about the eggs.

I tuned in "live" at 5 AM this morning -- eagles are busy in the morning, like all birds. It was interesting to hear the one on the nest call and call (either for a meal, or for relief of duty so she could fly and fish) and the mate respond from near by ... but he didn't come in right away.

If there are any early risers out there, they have a distinct advantage if they check the eagle cam with their first cup of coffee!!

Jane

5:36 AM  
Anonymous Anonymous said...

I greatly appreciate the comments in the blog about staying clear of nests, behavior of eagles when humans get too close. We're so far removed from our "natural heritage" we often humanize animal behavior and assume that their actions are akin to what WE would do to attract attention, etc. Thank you for educating interested readers.

10:20 AM  
Anonymous Anonymous said...

great work you are doing. i and my children love checking on the eagles and are anxiously awaiting the hatchlings. just want to let you know your work is greatly appreciated.

8:20 PM  
Anonymous Jane Edwards said...

Maybe you should let viewers know that the eaglets still have to be protected by the parents after they hatch, until they get their second feathers, if it's cold or rainy. So viewers will continue to see an eagle sitting on the nest a lot of the time, won't they?

Also, if there's a second eaglet, it will hatch later, as you said, and it will need protection for longer, too, won't it? Or don't the adults allow for that, once it's hatched?

I can't wait to see them feeding a little eaglet! Do you think we'll be able to see down into the nest? I have seen them tearing up a fish and handing it down into the nest, but never have seen the eaglets that small.

Jane Edwards
BE 251

4:27 PM  
Anonymous Anonymous said...

Hello, I've recently found about your web-site and find it very interesting. It's nice to know that someone cares enough to do this. Ericka

8:26 AM  
Anonymous Anonymous said...

I'm having a wonderful time watching the pair of eagles. I'm a speech therapist in Athens, Georgia and I've included the eagles in my lessons. We are very excited and hopeful for the babies and parents. I wish I could get the live web feed but I'm only able to see the still picture. Still very neat...
Thank you so much for allowing us to share this event.

Thanks, Jenny Tackett

1:28 PM  
Anonymous Anonymous said...

HI, On April 7, I saw the eagle that was sitting on the nest, flatten out her wings, walk in a circle in the nest, while squawking then she left for about 1 minute and 30 seconds. thanks

11:34 AM  
Anonymous Anonymous said...

you have a great thing going here PLESE KEEP IT UP for the sake of our youth.

9:26 AM  
Anonymous Anonymous said...

Thank you so much for doing this. We just found the sight about a week ago. It is so interesting I check on them several times a day. I have caught feeding time a couple of times now, those little guys really go after the food. We will continue to watch them grow and mature. Again many thanks, I have told many people to tune in for the show

7:45 PM  
Blogger kenn1324 said...

thanks guy i love eagles there a beautiful bird of prey this is a great site

9:48 AM  
Anonymous Anonymous said...

May 17th, 7:40 pm. Boy the eaglets are really getting big. I have been watching since there were just eggs in the nest. It is comical to watch them when they spread their wings out, (they sure have some big wings now!!!)it is as if they don't know how to fold those big wings back against their bodies. They also look as if they are now getting feathers. The adult eagles seem to be leaving them for longer and longer periods of time now, and the eaglets are moving sticks and things around in the nest like the adults do. : ) CS

7:42 PM  

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